1Place potatoes in enough water to cover (salted if desired) in 3-quart saucepan. Cover and heat to boiling. Boil about 15 minutes or until almost tender; drain. Cool slightly.
2Heat coals or gas grill for direct heat.
3Heat remaining ingredients to boiling; remove from heat. Cut each potato lengthwise into 4 or 5 slices. Brush potatoes generously with butter mixture.
4Cover and grill potatoes 4 inches from medium heat about 20 minutes, turning and brushing 2 or 3 times with butter mixture, until golden brown and tender.